US9366267B2 - Hydraulic unit - Google Patents

Hydraulic unit Download PDF

Info

Publication number
US9366267B2
US9366267B2 US14/345,109 US201214345109A US9366267B2 US 9366267 B2 US9366267 B2 US 9366267B2 US 201214345109 A US201214345109 A US 201214345109A US 9366267 B2 US9366267 B2 US 9366267B2
Authority
US
United States
Prior art keywords
tank
hydraulic
temperature
oil
power module
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US14/345,109
Other languages
English (en)
Other versions
US20140260234A1 (en
Inventor
Tetsuo Nakata
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daikin Industries Ltd
Original Assignee
Daikin Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries Ltd filed Critical Daikin Industries Ltd
Assigned to DAIKIN INDUSTRIES, LTD. reassignment DAIKIN INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: NAKATA, TETSUO
Publication of US20140260234A1 publication Critical patent/US20140260234A1/en
Application granted granted Critical
Publication of US9366267B2 publication Critical patent/US9366267B2/en
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
    • F15B20/007—Overload
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/58—Cooling; Heating; Diminishing heat transfer
    • F04D29/5806—Cooling the drive system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B23/00—Pumping installations or systems
    • F04B23/02—Pumping installations or systems having reservoirs
    • F04B23/025—Pumping installations or systems having reservoirs the pump being located directly adjacent the reservoir
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B23/00—Pumping installations or systems
    • F04B23/02—Pumping installations or systems having reservoirs
    • F04B23/025—Pumping installations or systems having reservoirs the pump being located directly adjacent the reservoir
    • F04B23/026—Pumping installations or systems having reservoirs the pump being located directly adjacent the reservoir a pump-side forming a wall of the reservoir
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/06—Control using electricity
    • F04B49/065—Control using electricity and making use of computers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/26—Supply reservoir or sump assemblies
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B19/00—Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
    • F15B19/005—Fault detection or monitoring
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
    • F15B20/002—Electrical failure

Definitions

  • the present invention relates to hydraulic units each configured to feed hydraulic fluid in a tank to a hydraulic actuator, and more particularly to cost reduction.
  • Hydraulic units each configured to feed hydraulic fluid in a tank to a hydraulic actuator have been conventionally known.
  • PATENT DOCUMENT 1 describes a hydraulic unit of this type.
  • the hydraulic unit is an oil-hydraulic unit configured to feed hydraulic oil to an oil-hydraulic actuator, and includes a tank, a pump, a motor, and a power conversion device.
  • the power conversion device converts electric power into a predetermined power, and feeds the power to the motor to rotate the pump connected to the motor.
  • the pump sucks hydraulic oil in the tank, and discharges the hydraulic oil to feed the hydraulic oil to the oil-hydraulic actuator.
  • conventional hydraulic units including the oil-hydraulic unit of PATENT DOCUMENT 1 have each included a fluid temperature sensor for a tank to manage the fluid temperature in the tank. Furthermore, in order to prevent a power module of a power conversion device from being broken due to overheating of the power module, a special temperature sensor has been provided in the vicinity of or inside the power module to protect the power module from overheating. For this reason, it has been conventionally expensive to install such two temperature sensors, and it has been difficult to reduce the cost of hydraulic units.
  • a first aspect of the invention is directed to a hydraulic unit including: a tank ( 30 ) configured to store hydraulic fluid; a pump ( 23 ) configured to suck the hydraulic fluid through an outlet ( 34 ) of the tank ( 30 ); a feed passage ( 21 ) through which the hydraulic fluid sucked by the pump ( 23 ) is fed to a hydraulic actuator; a return passage ( 22 ) through which the hydraulic fluid is returned from the hydraulic actuator to a return port ( 33 ) of the tank ( 30 ); an electric motor ( 24 ) configured to rotate the pump ( 23 ); and a power conversion device ( 50 ) configured to convert electric power into a predetermined power and feed the converted power to the electric motor ( 24 ).
  • the power conversion device ( 50 ) includes a power module ( 53 ) including a heat dissipating section ( 35 a , 38 a ) facing the hydraulic fluid in the tank ( 30 ), and a temperature sensor ( 59 ) configured to detect a temperature of the power module ( 53 ), and the hydraulic unit further includes a fluid temperature estimator ( 76 ) configured to estimate a temperature of the hydraulic fluid in the tank ( 30 ) based on the temperature detected by the temperature sensor ( 59 ).
  • the heat dissipating section ( 35 a , 38 a ) of the power module ( 53 ) faces the hydraulic fluid in the tank ( 30 ).
  • the power module ( 53 ) is cooled by the hydraulic fluid. This allows the power module ( 53 ) to have substantially the same temperature as the hydraulic fluid in the tank ( 30 ).
  • the fluid temperature in the tank ( 30 ) is estimated based on the temperature detected by the power module ( 53 ).
  • the temperature of the power module ( 53 ) and the fluid temperature in the tank ( 30 ) are substantially equal to each other as described above, when the fluid temperature in the tank ( 30 ) is estimated based on the temperature detected by the power module ( 53 ), a small error is merely observed, and the fluid temperature in the tank ( 30 ) can be obtained as an estimate value. This eliminates the need for measuring the fluid temperature in the tank ( 30 ) with a special fluid temperature sensor unlike the conventional art.
  • the temperature sensor ( 59 ) may be provided on the heat dissipating section ( 35 a , 38 a ) of the power module ( 53 ).
  • the temperature sensor ( 59 ) is provided on the heat dissipating section ( 35 a , 38 a ) facing the hydraulic fluid in the tank ( 30 ). This facilitates allowing the temperature sensor ( 59 ) to accurately detect the fluid temperature in the tank ( 30 ), and allows the temperature detected by the temperature sensor ( 59 ) to be closer to the fluid temperature in the tank ( 30 ).
  • the heat dissipating section ( 35 a , 38 a ) of the power module ( 53 ) may be closer to the outlet ( 34 ) of the tank ( 30 ) than to the return port ( 33 ) thereof.
  • the heat dissipating section ( 35 a , 38 a ) is away from the return port ( 33 ). This reduces contact between hydraulic fluid that has just passed through the return port ( 33 ) and returned into the tank ( 30 ) and the heat dissipating section ( 35 a , 38 a ), and facilitates bringing hydraulic fluid that has been returned into the tank ( 30 ) and has been diffused therein into contact with the heat dissipating section ( 35 a , 38 a ).
  • the temperature sensor ( 59 ) detects the temperature of the power module ( 53 ) cooled by the diffused hydraulic fluid, and the fluid temperature estimator ( 76 ) derives the temperature of the diffused hydraulic fluid.
  • a baffle ( 39 ) may be provided in the tank ( 30 ) to regulate a flow of hydraulic fluid from the return port ( 33 ) to the outlet ( 34 ).
  • the baffle ( 39 ) is provided. This increases the period of time after hydraulic fluid is returned into the tank ( 30 ) and until the hydraulic fluid reaches the heat dissipating section ( 35 a , 38 a ), and during the period of time, the hydraulic fluid is adequately diffused.
  • the fluid temperature estimator ( 76 ) derives the temperature of the adequately diffused hydraulic fluid.
  • the power module ( 53 ) is provided on the heat dissipating section ( 35 a , 38 a ) facing hydraulic fluid in the tank ( 30 ).
  • the temperature of the power module ( 53 ) is detected, and the fluid temperature in the tank ( 30 ) is estimated based on the detected temperature.
  • the power module ( 53 ) is cooled by the hydraulic fluid, and the power module ( 53 ) has substantially the same temperature as the hydraulic fluid in the tank ( 30 ).
  • the fluid temperature in the tank ( 30 ) is estimated based on the detected temperature of the power module ( 53 ), and the fluid temperature in the tank ( 30 ) can be thus obtained as an estimate value with a small error.
  • the temperature sensor ( 59 ) configured to detect the temperature of the power module ( 53 ) is provided on the heat dissipating section ( 35 a , 38 a ) of the power module ( 53 ). This allows the temperature detected by the temperature sensor ( 59 ) to be closer to the fluid temperature in the tank ( 30 ), thereby enabling a more accurate estimation of the fluid temperature based on the temperature detected by the temperature sensor ( 59 ).
  • the heat dissipating section ( 35 a , 38 a ) of the power module ( 53 ) is closer to the outlet ( 34 ) of the tank ( 30 ) than to the return port ( 33 ) thereof. For this reason, after hydraulic fluid passing through the return port ( 33 ) and then returned into the tank ( 30 ) has been diffused, the hydraulic fluid is brought into contact with the heat dissipating section ( 35 a , 38 a ). Thus, even when high-temperature hydraulic fluid is returned into the tank ( 30 ), the returned high-temperature hydraulic fluid is diffused, and instead of the temperature of the high-temperature hydraulic fluid immediately after being returned, the average fluid temperature in the tank ( 30 ) can be obtained.
  • the baffle ( 39 ) is provided in the tank ( 30 ) to regulate the flow of hydraulic fluid from the return port ( 33 ) to the outlet ( 34 ). This allows the hydraulic fluid to be adequately diffused after the hydraulic fluid is returned into the tank ( 30 ) and until the hydraulic fluid reaches the heat dissipating section ( 35 a , 38 a ). This can further ensure that the average fluid temperature in the tank ( 30 ) is obtained.
  • FIG. 1 is a schematic view illustrating the entire configuration of an oil-hydraulic unit of an embodiment.
  • FIG. 2 is a perspective view illustrating the configuration of a tank of this embodiment.
  • FIG. 3 is a cross-sectional view illustrating the configuration of the tank of this embodiment.
  • FIG. 4 is a block diagram illustrating the circuit configuration of a power conversion device of this embodiment.
  • FIG. 5 is a cross-sectional view illustrating the configuration of a power module of this embodiment.
  • FIG. 6 is a flow chart illustrating control operation of an abnormal oil temperature sensor section of this embodiment.
  • FIG. 7 is a cross-sectional view illustrating the configuration of a tank of another embodiment.
  • FIG. 8 is a plan view illustrating the configuration of a tank of still another embodiment.
  • FIG. 9 is a cross-sectional view illustrating the configuration of a tank of yet another embodiment.
  • an oil-hydraulic unit ( 10 ) of this embodiment is configured to feed hydraulic oil to an oil-hydraulic actuator, such as an oil-hydraulic cylinder ( 1 ), and actuate the oil-hydraulic actuator.
  • the oil-hydraulic unit ( 10 ) forms a hydraulic unit of the present invention.
  • the oil-hydraulic unit ( 10 ) is incorporated into, for example, a machine tool, such as a machining center, and is connected to the oil-hydraulic cylinder ( 1 ) configured to open and close a chuck mechanism for pinching work or tools to fix them.
  • the oil-hydraulic unit ( 10 ) includes a tank ( 30 ), two oil channels (a feed passage ( 21 ) and a return passage ( 22 )) connecting the tank ( 30 ) to the oil-hydraulic cylinder ( 1 ), and a controller ( 70 ).
  • the feed passage ( 21 ) is one of the oil channels through which hydraulic oil is fed from the tank ( 30 ) to the oil-hydraulic cylinder ( 1 ), and the return passage ( 22 ) is the other one thereof through which hydraulic oil is returned from the oil-hydraulic cylinder ( 1 ) to the tank ( 30 ).
  • the feed passage ( 21 ) is connected to the pump ( 23 ), and the feed passage ( 21 ) and the return passage ( 22 ) are connected to a directional selector valve ( 25 ).
  • the pump ( 23 ) is a fixed displacement pump, such as a gear pump, a trochoid pump, a vane pump, or a piston pump, and is configured to suck hydraulic oil from the tank ( 30 ) and discharge the hydraulic oil into the oil-hydraulic cylinder ( 1 ).
  • a suction side of the pump ( 23 ) is connected to an outlet ( 34 ) of the tank ( 30 ) described below, and a discharge side thereof is connected to a port P of the directional selector valve ( 25 ) described below.
  • the pump ( 23 ) is connected to an electric motor ( 24 ) for rotating the pump ( 23 ).
  • the electric motor ( 24 ) is a variable speed motor, and the rotation of the electric motor ( 24 ) is controlled by a power conversion device ( 50 ).
  • the power conversion device ( 50 ) will be described below.
  • the directional selector valve ( 25 ) is a three-position, four-port spring centered electromagnetic selector valve including a first electromagnetic solenoid ( 25 a ) and a second electromagnetic solenoid ( 25 b ).
  • the port P is connected to the discharge side of the pump ( 23 )
  • a port T is connected to a return port ( 33 ) of the tank ( 30 ) described below.
  • a port A of the directional selector valve ( 25 ) is connected to a head chamber ( 1 a ) of the oil-hydraulic cylinder ( 1 )
  • a port B thereof is connected to a rod chamber ( 1 b ) of the oil-hydraulic cylinder ( 1 ).
  • the directional selector valve ( 25 ) is selectable among a neutral position, a first position, and a second position, based on on-off operation of each of the electromagnetic solenoids ( 25 a , 25 b ).
  • the directional selector valve ( 25 ) is in the neutral position, the four ports are disconnected from one another.
  • the directional selector valve ( 25 ) is in the first position, the ports P and A communicate with each other, and the ports B and T communicate with each other.
  • the directional selector valve ( 25 ) is in the second position, the ports P and B communicate with each other, and the ports A and T communicate with each other.
  • the tank ( 30 ) is configured to store hydraulic oil, and includes a rectangular tank body ( 31 ) which has an open upper end and in which hydraulic oil is stored, and a lid body ( 32 ) blocking the upper end of the tank body ( 31 ).
  • the lid body ( 32 ) includes the return port ( 33 ) and the outlet ( 34 ) both passing therethrough.
  • the return port ( 33 ) is close to a left side wall of the tank body ( 31 ) (see FIG. 3 ), and is connected to a pipe (the return passage ( 22 )) extending from the port T of the directional selector valve ( 25 ).
  • the outlet ( 34 ) is close to a right side wall of the tank body ( 31 ) (see FIG. 3 ), and is connected to a pipe (the feed passage ( 21 )) extending to the suction side of the pump ( 23 ).
  • the right side wall of the tank body ( 31 ) is recessed inward to form a box-shaped recess ( 35 ), and the tank body ( 31 ) further includes a plate ( 36 ) blocking an opening of the recess ( 35 ).
  • the recess ( 35 ) and the plate ( 36 ) forms a control box ( 37 ).
  • the control box ( 37 ) (the recess ( 35 )) is closer to the outlet ( 34 ) of the tank ( 30 ) than to the return port ( 33 ) thereof, and faces the stored hydraulic oil.
  • the power conversion device ( 50 ) is housed in the control box ( 37 ).
  • the power conversion device ( 50 ) is a so-called inverter configured to convert power supplied from an alternating-current power supply into a predetermined power. As illustrated in FIG. 4 , the power conversion device ( 50 ) includes a converter circuit ( 51 ) and an inverter circuit ( 52 ).
  • the converter circuit ( 51 ) is connected to the alternating-current power supply (e.g., a three-phase electric power of 200V), and converts the alternating current into direct current.
  • the inverter circuit ( 52 ) converts the output of the converter circuit ( 51 ) into power having a predetermined frequency based on on-off operation of a switching element (not shown), and the converted power is supplied to the electric motor ( 24 ).
  • the on-off operation of the switching element is controlled by a power controller section ( 71 ) of the controller ( 70 ) described below.
  • the power conversion device ( 50 ) includes a substrate ( 57 ), a power module ( 53 ), electronic components ( 58 ) except the power module ( 53 ), and a temperature sensor ( 59 ).
  • the power module ( 53 ) is an electronic component, such as an insulated-gate bipolar transistor (IGBT) or a power metal oxide semiconductor field-effect transistor (MOSFET), including at least one power semiconductor ( 55 ) generating a large amount of heat when energized.
  • the power module ( 53 ) includes a base plate ( 54 ) fixed to the bottom surface (the inner surface of a bottom wall ( 35 a )) of the recess ( 35 ), and the at least one power semiconductor ( 55 ) is disposed on the base plate ( 54 ).
  • the heat is transferred from the base plate ( 54 ) to the bottom wall ( 35 a ) of the recess ( 35 ), and is dissipated into hydraulic oil in the tank ( 30 ).
  • the bottom wall ( 35 a ) of the recess ( 35 ) forms a heat dissipating section of the power module ( 53 ) of the present invention.
  • the substrate ( 57 ) is fixed on the power module ( 53 ).
  • the power module ( 53 ) is mounted on the back surface (the left surface in FIG. 3 ) of the substrate ( 57 ), and the other electronic components ( 58 ) are mounted on the front surface (the right surface in FIG. 3 ) thereof, thereby forming the converter circuit ( 51 ) and the inverter circuit ( 52 ).
  • the other electronic components ( 58 ) are surface mount devices, such as a non-power semiconductor, a capacitor, and/or a resistor, and generate a relatively small amount of heat when energized.
  • the temperature sensor ( 59 ) is a contact temperature sensor that is, for example, a thermistor or a resistance thermometer.
  • the temperature sensor ( 59 ) is configured to detect the temperature of the power module ( 53 ), and is fixed to a region of the bottom surface of the recess ( 35 ) near the power module ( 53 ). Furthermore, the temperature sensor ( 59 ) is configured to output a detected value T to an oil temperature estimator ( 76 ) of the controller ( 70 ) described below.
  • the controller ( 70 ) includes the power controller section ( 71 ) and the abnormal oil temperature sensor section ( 75 ).
  • the power controller section ( 71 ) controls on-off operation of the switching element of the inverter circuit ( 52 ). Specifically, the power controller section ( 71 ) receives the detected rotational speed of the electric motor ( 24 ) and a target rotational speed (a set value) to perform proportional-integral (PI) control. Thus, a control signal for performing on-off operation of the switching element is generated, and the control signal is output to the inverter circuit ( 52 ).
  • PI proportional-integral
  • the abnormal oil temperature sensor section ( 75 ) is configured to sense whether the oil temperature in the tank ( 30 ) is abnormal, and includes the oil temperature estimator ( 76 ), an abnormality determiner ( 77 ), and an alarm ( 78 ).
  • the oil temperature estimator ( 76 ) calculates the estimate oil temperature Tes in the tank ( 30 ) based on the value T detected by the temperature sensor ( 59 ).
  • the oil temperature estimator ( 76 ) forms a fluid temperature estimator of the present invention.
  • the estimate oil temperature Tes is output to the abnormality determiner ( 77 ).
  • the abnormality determiner ( 77 ) compares the estimate oil temperature Tes calculated by the oil temperature estimator ( 76 ) to a predetermined threshold value Tsh to determine whether or not the oil temperature is abnormal. When the abnormality determiner ( 77 ) determines that the oil temperature is abnormal, the determination result is output to the alarm ( 78 ).
  • the alarm ( 78 ) receives the determination result in which the oil temperature is abnormal from the abnormality determiner ( 77 ), thereby issuing an alarm about the situation where the oil temperature is abnormal.
  • a display such as a warning lamp, or a sound producer, such as a beeper, may be used as a means by which the alarm ( 78 ) issues an alarm.
  • the power conversion device ( 50 ) converts electric power, and the converted electric power is fed to the electric motor ( 24 ), the pump ( 23 ) connected to the electric motor ( 24 ) is rotated.
  • the pump ( 23 ) sucks hydraulic oil in the tank ( 30 ) and discharges the hydraulic oil to feed the hydraulic oil to the oil-hydraulic cylinder ( 1 ).
  • the power module ( 53 ) of the power conversion device While hydraulic oil is fed as above, the power module ( 53 ) of the power conversion device generates heat.
  • the power module ( 53 ) is provided on the bottom surface (the inner surface of the bottom wall ( 35 a )) of the recess ( 35 ) facing hydraulic oil in the tank ( 30 ). For this reason, even if the power module ( 53 ) generates heat, the heat is removed by the hydraulic oil in the tank ( 30 ). This allows the power module ( 53 ) to keep having substantially the same temperature as the hydraulic oil in the tank ( 30 ).
  • the pressure of hydraulic oil is increased, and the hydraulic oil increased in pressure is fed to the oil-hydraulic cylinder ( 1 ). This increases the temperature of the hydraulic oil.
  • the abnormal oil temperature sensor section ( 75 ) derives the estimate oil temperature Tes in the tank ( 30 ), and senses whether the oil temperature is abnormal based on the estimate oil temperature Tes.
  • the abnormal oil temperature sensor section ( 75 ) senses whether the oil temperature in the tank ( 30 ) is abnormal.
  • step ST 1 the temperature of the power module ( 53 ) is detected by the temperature sensor ( 59 ).
  • the detected value T is input to the oil temperature estimator ( 76 ).
  • step ST 2 the oil temperature estimator ( 76 ) derives the estimate oil temperature Tes in the tank ( 30 ). Specifically, an operation is performed on the detected value T in step ST 1 and several parameters (e.g., the thickness and thermal conductivity of the bottom wall ( 35 a )), thereby deriving the estimate oil temperature Tes.
  • the estimate oil temperature Tes is output to the abnormality determiner ( 77 ).
  • step ST 3 the abnormality determiner ( 77 ) compares the estimate oil temperature Tes calculated in step ST 2 to the predetermined threshold value Tsh to determine whether or not the oil temperature is abnormal. Specifically, when the state in which the estimate oil temperature Tes is greater than the predetermined threshold value Tsh continues over a predetermined period of time, it is determined that the oil temperature is abnormal. This process proceeds to step ST 4 . In contrast, when the estimate oil temperature Tes is not greater than the predetermined threshold value Tsh, or when the state in which the estimate oil temperature Tes is greater than the predetermined threshold value Tsh does not continue over a predetermined or longer period of time, it is not determined that the oil temperature is abnormal. This process returns to step ST 1 .
  • step ST 4 the determination result in which the oil temperature is abnormal is input to the alarm ( 78 ), thereby issuing an alarm about the situation where the oil temperature is abnormal.
  • the abnormal oil temperature sensor section ( 75 ) repeatedly performs steps ST 1 through ST 3 at predetermined time intervals during operation of the oil-hydraulic unit ( 10 ) to repeatedly determine whether or not the oil temperature is abnormal. If it is determined that the oil temperature is abnormal, an alarm about the situation where the oil temperature is abnormal is issued in step ST 4 .
  • the power module ( 53 ) is provided on the bottom wall ( 35 a ) of the recess ( 35 ) facing hydraulic oil in the tank ( 30 ).
  • the temperature of the power module ( 53 ) is detected, and the oil temperature in the tank ( 30 ) is estimated based on the detected value T.
  • the power module ( 53 ) is cooled by the hydraulic oil, and the power module ( 53 ) has substantially the same temperature as the hydraulic oil in the tank ( 30 ).
  • the oil temperature in the tank ( 30 ) is estimated based on the detected temperature of the power module ( 53 ), and the oil temperature in the tank ( 30 ) can be thus obtained as the estimate oil temperature Tes with a small error.
  • the temperature sensor ( 59 ) configured to detect the temperature of the power module ( 53 ) is provided on the bottom wall ( 35 a ) of the recess ( 35 ) on which the power module ( 53 ) is also provided. This allows the temperature detected by the temperature sensor ( 59 ) to be closer to the oil temperature in the tank ( 30 ), thereby enabling a more accurate estimation of the oil temperature based on the temperature detected by the temperature sensor ( 59 ).
  • the bottom wall ( 35 a ) of the recess ( 35 ) on which the power module ( 53 ) is provided is closer to the outlet ( 34 ) of the tank ( 30 ) than to the return port ( 33 ) thereof. For this reason, after hydraulic oil passing through the return port ( 33 ) and then returned into the tank ( 30 ) has been diffused, the hydraulic oil can be brought into contact with the bottom wall ( 35 a ). Thus, even when high-temperature hydraulic fluid is returned into the tank ( 30 ), the returned high-temperature hydraulic oil is diffused, and thereafter, instead of the temperature of the high-temperature hydraulic oil immediately after being returned, the average oil temperature in the tank ( 30 ) can be obtained.
  • the embodiment may be configured as below.
  • an operation is performed on the value T detected by the temperature sensor ( 59 ) and several parameters (e.g., the thickness and thermal conductivity of the bottom wall ( 35 a )), thereby deriving the estimate oil temperature Tes.
  • a process for deriving the estimate oil temperature Tes is not limited to the above process.
  • a table indicating the relationship between the value T detected by the temperature sensor ( 59 ) and the oil temperature in the tank ( 30 ) may be previously prepared, and the estimate oil temperature Tes may be derived with reference to the table.
  • the value T detected by the temperature sensor ( 59 ) may be used as the estimate oil temperature Tes without being changed.
  • an object configured to regulate the flow of hydraulic oil is not provided between the return port ( 33 ) and outlet ( 34 ) of the tank ( 30 ).
  • a baffle or baffles ( 39 ) may be provided such that hydraulic oil meanders between the return port ( 33 ) and the outlet ( 34 ).
  • the baffle ( 39 ) may be provided such that hydraulic oil returned into the tank ( 30 ) crosses over the baffle ( 39 ), and flows to the outlet ( 34 ).
  • the baffles ( 39 ) may be provided such that hydraulic oil returned into the tank ( 30 ) meanders in lateral directions.
  • the provision of the baffle or baffles ( 39 ) allows the hydraulic oil to be adequately diffused after the hydraulic oil is returned into the tank ( 30 ) and until the hydraulic oil reaches the bottom wall ( 35 a ) of the recess ( 35 ). This can ensure that instead of the temperature of the hydraulic oil immediately after being returned, the average oil temperature in the tank ( 30 ) is obtained.
  • the recess ( 35 ) and the plate ( 36 ) form the control box ( 37 ).
  • a box ( 38 ) may be inserted into the recess ( 35 ), and the recess ( 35 ) and the box ( 38 ) may form the control box ( 37 ).
  • the power module ( 53 ) is provided on the inner surface of a back plate ( 38 a ) of the box ( 38 ), and the heat dissipating section of the power module ( 53 ) of the present invention includes the bottom wall ( 35 a ) of the recess ( 35 ) and the back plate ( 38 a ) of the box ( 38 ) being in close contact with the bottom wall ( 35 a ).
  • the temperature sensor ( 59 ) is provided on the bottom surface (the inner surface of the bottom wall ( 35 a )) of the recess ( 35 ) on which the power module ( 53 ) is also provided.
  • the location at which the temperature sensor ( 59 ) is provided is not limited to the above location. As long as the temperature sensor ( 59 ) is provided at a location at which the temperature of the power module ( 53 ) can be detected, the temperature sensor ( 59 ) may be provided, for example, inside the power module ( 53 ) or on a surface different from the surface on which the power module ( 53 ) is provided.
  • the hydraulic unit according to the present invention is useful as an oil-hydraulic unit configured to feed hydraulic oil to an oil-hydraulic actuator.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Computer Hardware Design (AREA)
  • Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Details Of Reciprocating Pumps (AREA)
US14/345,109 2011-09-27 2012-09-24 Hydraulic unit Active 2033-08-10 US9366267B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2011210384A JP5141810B1 (ja) 2011-09-27 2011-09-27 液圧ユニット
JP2011-210384 2011-09-27
PCT/JP2012/006062 WO2013046630A1 (ja) 2011-09-27 2012-09-24 液圧ユニット

Publications (2)

Publication Number Publication Date
US20140260234A1 US20140260234A1 (en) 2014-09-18
US9366267B2 true US9366267B2 (en) 2016-06-14

Family

ID=47789861

Family Applications (1)

Application Number Title Priority Date Filing Date
US14/345,109 Active 2033-08-10 US9366267B2 (en) 2011-09-27 2012-09-24 Hydraulic unit

Country Status (6)

Country Link
US (1) US9366267B2 (ja)
JP (1) JP5141810B1 (ja)
KR (1) KR101568950B1 (ja)
CN (1) CN103827513B (ja)
TW (1) TWI465648B (ja)
WO (1) WO2013046630A1 (ja)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102046657B1 (ko) * 2013-04-16 2019-11-19 두산인프라코어 주식회사 유압장치의 과열방지 시스템
CN107795531A (zh) * 2017-11-13 2018-03-13 邯郸钢铁集团有限责任公司 一种保持倒角板坯二次压角液压稳定的系统及其使用方法
JP2020120507A (ja) * 2019-01-24 2020-08-06 ヤンマーパワーテクノロジー株式会社 作業機械
KR102174359B1 (ko) * 2019-02-19 2020-11-04 (주)다산이엔지 진공 게이트 밸브

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63282063A (ja) 1987-05-14 1988-11-18 三菱電機株式会社 油圧エレベ−タの油温検出装置
JPH0457685U (ja) 1990-09-21 1992-05-18
JPH08109872A (ja) 1994-10-13 1996-04-30 Sanyo Electric Co Ltd ポンプ装置
JPH11313466A (ja) 1998-04-28 1999-11-09 Shibaura Mechatronics Corp モータおよびポンプ装置
JP2005016596A (ja) 2003-06-24 2005-01-20 Tokimec Inc 液圧装置
JP2006258271A (ja) 2005-03-18 2006-09-28 Toyooki Kogyo Co Ltd 油圧装置
JP4245065B2 (ja) 2007-06-07 2009-03-25 ダイキン工業株式会社 流体圧ユニット
US8696331B2 (en) * 2008-05-06 2014-04-15 Fmc Technologies, Inc. Pump with magnetic bearings

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6259301U (ja) * 1985-10-02 1987-04-13
JP4493061B2 (ja) * 1999-04-22 2010-06-30 油研工業株式会社 電動機内蔵油圧ポンプ
JP3971656B2 (ja) * 2002-06-03 2007-09-05 本田技研工業株式会社 エンジンにおけるエンジン温度検出装置
CN2771538Y (zh) * 2005-02-28 2006-04-12 夏连根 内置浸油式一体化液压动力单元
JP5194766B2 (ja) * 2007-12-19 2013-05-08 パナソニック株式会社 インバータ一体型電動圧縮機
CN101949395B (zh) * 2010-09-19 2012-11-07 北京建筑工程学院 液压系统用散热式油箱

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63282063A (ja) 1987-05-14 1988-11-18 三菱電機株式会社 油圧エレベ−タの油温検出装置
JPH0457685U (ja) 1990-09-21 1992-05-18
JPH08109872A (ja) 1994-10-13 1996-04-30 Sanyo Electric Co Ltd ポンプ装置
JPH11313466A (ja) 1998-04-28 1999-11-09 Shibaura Mechatronics Corp モータおよびポンプ装置
JP2005016596A (ja) 2003-06-24 2005-01-20 Tokimec Inc 液圧装置
JP2006258271A (ja) 2005-03-18 2006-09-28 Toyooki Kogyo Co Ltd 油圧装置
JP4245065B2 (ja) 2007-06-07 2009-03-25 ダイキン工業株式会社 流体圧ユニット
US20100154398A1 (en) 2007-06-07 2010-06-24 Yoshiyuki Ochi Fluid pressure unit
US8696331B2 (en) * 2008-05-06 2014-04-15 Fmc Technologies, Inc. Pump with magnetic bearings

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
International Search Report issued in PCT/JP2012/006062 mailed Oct. 23, 2012.

Also Published As

Publication number Publication date
KR101568950B1 (ko) 2015-11-12
CN103827513A (zh) 2014-05-28
TW201333332A (zh) 2013-08-16
CN103827513B (zh) 2015-11-25
US20140260234A1 (en) 2014-09-18
KR20140063879A (ko) 2014-05-27
JP2013072453A (ja) 2013-04-22
WO2013046630A1 (ja) 2013-04-04
JP5141810B1 (ja) 2013-02-13
TWI465648B (zh) 2014-12-21

Similar Documents

Publication Publication Date Title
US9366267B2 (en) Hydraulic unit
JP6987220B6 (ja) 電動モータの冷却方法および冷却装置
CA3025638C (en) Temperature abnormality detection method for power conversion apparatus and temperature abnormality detection device for power conversion apparatus
KR101749819B1 (ko) 차재용 전동 압축기의 제어 장치
JP2022161899A (ja) パワートレイン、冷媒流量推定方法、および電動車両
US20210333157A1 (en) Method and system for estimating junction temperature of power semiconductor device of power module
JP6245088B2 (ja) 冷却器
JP6653609B2 (ja) インバータ冷却装置の水抜け検知装置
JP6637812B2 (ja) 半導体装置
JP2015208081A (ja) 半導体素子温度推定装置
CN110614919B (zh) 冷却液流量监测方法及液冷电驱系统
KR20160091002A (ko) 냉각수 가열식 히터의 안전 제어 방법 및 장치
JP6360032B2 (ja) モータ温度及びアンプ温度に応じて動作を変更する機能を有する工作機械の制御装置
JP5287159B2 (ja) 電力変換装置
JP2020071093A (ja) 電流センサ
JP2007010436A (ja) 温度推定装置
JP2010041005A (ja) 沸騰冷却装置
JP6158881B2 (ja) インバータの保護方法に特徴を有するモータの制御方法
JP2013254899A (ja) 冷却装置および流体圧ユニット
JP2018038194A (ja) 電力変換装置
TWI730404B (zh) 定壓液體供給裝置
US20220140455A1 (en) Device and method for measuring the temperature of a cooling medium for an inverter, inverter with such a device
JP2022138411A (ja) 流量推定装置、車両および流量推定方法
JP2014034911A (ja) モータ制御装置および電動ポンプユニット
JP2021038702A (ja) 定圧液供給装置

Legal Events

Date Code Title Description
AS Assignment

Owner name: DAIKIN INDUSTRIES, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NAKATA, TETSUO;REEL/FRAME:032473/0079

Effective date: 20121218

STCF Information on status: patent grant

Free format text: PATENTED CASE

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 4

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 8